Least Cost Routing; Overview - AudioCodes Mediant 500L User Manual

From: John Doe <sip:4064@company.com>
Note:
•
The Calling Name Manipulation for Tel-to-IP Calls table uses the numbers before
manipulation, as inputs.
•
The LDAP query uses the calling number after source number manipulation, as
the search key value.
•
The feature is applicable only to the Gateway application.
15.5

Least Cost Routing

This section provides a description of the device's least cost routing (LCR) feature and how
to configure it.

15.5.1 Overview

The LCR feature enables the device to choose the outbound IP destination routing rule
based on lowest call cost. This is useful in that it enables service providers to optimize
routing costs for customers. For example, you may wish to define different call costs for
local and international calls or different call costs for weekends and weekdays (specifying
even the time of call). The device sends the calculated cost of the call to a Syslog server
(as Information messages), thereby enabling billing by third-party vendors.
LCR is implemented by defining Cost Groups and assigning them to routing rules in the
Tel-to-IP Routing table (Gateway calls) or IP-to-IP Routing table (SBC calls). The device
searches the routing table for matching routing rules and then selects the rule with the
lowest call cost. If two routing rules have identical costs, the rule appearing higher up in the
table is used (i.e., first-matched rule). If the selected route is unavailable, the device selects
the next least-cost routing rule.
Even if a matched routing rule is not assigned a Cost Group, the device can select it as the
preferred route over other matched rules that are assigned Cost Groups. This is
determined according to the settings of the 'Default Call Cost' parameter configured for the
Routing Policy (associated with the routing rule for SBC calls). To configure the Routing
Policy, see Configuring a Gateway Routing Policy Rule on page 523 (for Gateway) and
Configuring SBC Routing Policy Rules on page 705 (for SBC).
The Cost Group defines a fixed connection cost (connection cost) and a charge per minute
(minute cost). Cost Groups can also be configured with time segments (time bands), which
define connection cost and minute cost based on specific days of the week and time of day
(e.g., from Saturday through Sunday, between 6:00 and 18:00). If multiple time bands are
configured per Cost Group and a call spans multiple time bands, the call cost is calculated
using only the time band in which the call was initially established.
In addition to Cost Groups, the device can calculate the call cost using an optional, user-
defined average call duration value. The logic in using this option is that a Cost Group may
be cheap if the call duration is short, but due to its high minute cost, may prove very
expensive if the duration is lengthy. Thus, together with Cost Groups, the device can use
this option to determine least cost routing. The device calculates the Cost Group call cost
as follows:
Total Call Cost = Connection Cost + (Minute Cost * Average Call Duration)
The below table shows an example of call cost when taking into consideration call duration.
This example shows four defined Cost Groups and the total call cost if the average call
duration is 10 minutes:
User's Manual
Mediant 500L Gateway & E-SBC
276 Document #: LTRT-10532